| |
| |
|
Is import of goods from european countries to Czech republic more or less influenced by changes in nominal and real exchange rates than in non european countries?
Vereš, Jan ; Stroukal, Dominik (advisor) ; Slaný, Martin (referee)
This bachelor thesis analyses the connection between import of goods from foreign countries to Czech Republic and the exchange rate changes. The initial hypothesis of this paper is to prove that the depreciation of domestic currency has positive influence on balance of trade balance. For this purpose there is eight econometric models which were created by using time series from years 2003 to 2016. These models are divided in pairs among four chosen countries. For each country two models were created that follow the development of trade balance between Czech Republic and one of the countries in two different time frames. All the models always use the real effective exchange rate, growth rate of GDP for Czech Republic and growth rate of GDP for one of the countries as explanatory variable. It is connected with the second task of this thesis, which is the analysis of the differences in the behaviour of the models that belong to the countries which are members of the EU and these that are not. The aim is to find out whether the existence of tariffs on imported goods from countries out of the EU causes visible differences in the behaviour of the variables that were included in the models. Based on the outcomes of all eight models the main hypothesis has been proved right for three out of four countries. In the models for Germany, China and France the relation of real exchange rate and trade balance came out as positive in long term, in short term the outcome was ambiguous. The second question of this thesis has been answered, but its added value is questionable. The final models for each state do show some noticeable differences and they can be used to determine if the influence of the change of exchange rates on trade balance is smaller or bigger in the countries where tariffs are used. On the other hand, from the results we can learn that the sample of only four countries is insufficient for the deduction of any conclusions.
|
|
Numerical analysis of a surface crack propagation in protective layers
Majer, Zdeněk
The paper contains a numerical analysis of a surface crack propagation in an elastic surface layer. It was analysed an influence of elastic material parameters of both system components, initial length and orientation of crack on fatigue crack propagation direction. The typical behaviour of crack propagation in thin layers was described. The finite element method for determination of the direction of the farther crack propagation was used.
|
|
The natural seasonal changes in the food choice and digestive tract of wild ruminants
Kamler, Jiří ; Homolka, Miloslav
Herbivore populations all over Europe have been strongly influenced by human activities. A combination of harvest, changes in forest structure, supplementary feeding, predator extirpation and others factors have led in most cases to increases of their populations and a severe impact on the composition and structure of the forest vegetation. The food choice of free living ungulate species is strongly influenced by season and animal species and changes in diet composition and quality cause the changes in the digestive tract. Effective management of ungulate populations and forest ecosystems should be based not only on detailed information about the impact of deer browsing and the number of deer to harvest but also on the density of deer species, the food supply, the structure of diets consumed by individual species, attraction and quality of the individual components of food supply the total quality of food taken and seasonal changes in digestive tract.
|
| |
|
Creep Behaviour of Aluminium after Severe Plastic Deformation (ECAP)
Král, Petr ; Dvořák, Jiří ; Svoboda, Milan ; Sklenička, Václav
In this work the behaviour of ECAP aluminium with different number of passes at the creep tests was studied. The data indicated that an increase fraction of high angle boundaries has a strong effect on the creep properties of ECAP aluminium which can be explained by extensive grain boundary sliding contributing to the total creep deformation. However, the samples of ECAP aluminium with the identical number of ECAP passes showed significant differences of creep properties. The observed scatter in the creep behaviour is probably a direct consequence of different microstructures in the as-pressed state after ECAP.
|
|
Influence of Microstructure Changes on the Mechanical Behaviour of Aluminium Processed by ECAP Method
Král, Petr ; Dvořák, Jiří ; Svoboda, Milan ; Sklenička, Václav
Extremely coarse – grained aluminium (99.99 %) was subjected to severe plastic deformation (Equal-Channel Angular Pressing) at room temperature. The properties of the ECAP material may considerably differ from properties of material with a standard coarse grain size. The largest changes of microstructure take place during the first four ECAP passes. Thus, the microstructure after twelve passes consists of roughly equiaxed grains (~m) with high fraction of high angle boundaries (~70%). In this work the behaviour of ECAP material with different number of passes at the tensile and creep tests has been studied. It is shown that ECAP aluminum provides a significant increase of the ultimate strength, however, there is low strain hardening during tensile deformation. The creep resistance of aluminum increased considerably already after one ECAP pass. However, repetitive ECAP pressing lead to a noticeable degrease in the creep properties. ECAP microstructure was examined in terms of the inhomogeneity. The results indicate that an inhomogeneity of the ECAP microstructure may influence the creep behaviour of the ECAP material.
|
|
Reliability assessment of bodies with general singular stress concentrator
Klusák, Jan
The paper presents a method leading to reliability assessment of bodies with general singular stress concentrator. The method uses combination of analytical and numerical procedures to determine fracture-mechanics parameters. The approach is based on comparison of fracture behaviour of body with a crack and a body with a general singular stress concentrator. The goal of the paper is to determine value of applied stress that leads to initiation of failure of construction.
|
|
The influence of coatings on fracture behaviour of ledeburitic steel
Šafář, Martin ; Jurči,, Peter (referee) ; Hadraba, Hynek (advisor)
This work deals with tool steel Vanadis 6. It describes the preparation of samples for the three-point bending test, with which it examines the influence of surface roughness, the effect of nitriding, coating and duplex coatings on fracture behaviour of the steel. First, it examines bending strength and the total energy required to work of fracture. The work also includes mapping and measurement of surface roughness on different layers. This measurement is performed on a confocal microscope.
|
guest ::
